Method and apparatus for forming sheet glass



Jan. 31, 1933. 'c. CONE 1,895,916

METHOD AND APPARATUS FOR FORMING SHEET GLASS Filed Sept. 16, 1951 3 Sheets-Sheet l lhmentor Carroll Cone g, g y

' 1 Gttomcg Jan. 31, 1933. c. CONE 1,895,916

METHOD AND APPARATUS FOR FORMING SHEET G LASS Filed Sept. 16, 1931 3 Sheets-Sheet Bummer Carroll Cone Jan. 31, 1933.

Filed C. CONE METHOD AND APPARATUS FOR FORMING SHEET GLASS Sept.

16 1931 3 Sheets-Sheet 3 3nnentor Carroll Come Patented Jan. 31, 1933 UNITED STATES PATENT OFFICE- CABBOLL CONE, OI TOLEDO, OHIO, ASSIGNOR TO LIBBEY-OWENS-FOBD GLASS COEPANY,

OF TOLEDO, OHIO, A CORPORATION OF OHIO METHOD AND APPARATUS FOR FORMING SHEET GLASS Application flled September 16, 1931. Serial No. 563,049.

The present invention relates to an improved method and apparatus for forming sheet or plate glass by a rolling operation.

In rolling sheets of material, especially when the operation is performed on hot stock such as glass, considerable trouble is experienced from deflection and deformation of the forming rolls which distort the cross section of the resulting sheet. The two sides of the sheet may be controlled in thickness by independently varying the pressure forcing the two ends of the forming rolls together. The center of the sheet, however, may be thicker or thinner than the edges, depending upon theproportions of the rolls and the operating conditions. Among the factors tending to introduce variations of this sort are the pressure tending to bow the rolls apart, which would give a thicker center; the increase in diameter of the rolls due to thermo-expansion, which is usually greatest at the center and tends to reduce the thickness of the sheet at this point; and the fact that with hot maerials, both rolls tend to be permanently hotter on the side in contact with the sheet, causing a warping together which reduces the gap between the rolls at the center of said sheet.

Heretofore, the practice has been either to so proportion the rolls as to make the abovementioned influences balance one another for average operating conditions, or to vary the roll diameters from the center to the end, arriving at the best average contours by trial. The first method imposes serious limitations on the design and must usually be carried through several trials to strike a desirable average. The second method is obviously slow and expensive. Neither procedure will accommodate changes in operating temperatures, speeds and pressures without replacing the rolls.

The aim and principal object of this invention lies in the provision of a method and apparatus for maintaining the sheet forming pass or gap between the forming rolls of a uniform width throughout during the rolling operation by varying the normal shape of the pass to meet different operating conditions, to the end that the sheet produced will be of a uniform thickness throughout its entire width.

Another important objectof the invention is the provision of a method and apparatus by which the normal shape of the pass or gap between the sheet forming rolls may be varied by a simple adjustment of the said rolls so as to change the relative width at the center and at the ends and without the necessity of removing the rolls or altering their shape.

Other objects and advantages of the invention will become more apparent during the course of the following description when taken in connection with the accompanying drawings.

In the drawings formin a part of this application and wherein 1i e numerals are employed to designate like parts throughout the same,

Fig. 1 is a vertical longitudinal section through a sheet rolling mechanism provided by the present invention,

Fig. 2 is an end elevation thereof, partially broken away,

Fig. 3 is a front view of the forming rolls,

Fig. 4 is an end view of Fig. 3,

Fig. 5 is a view similar to Fig. 3, but showing the rolls crossed in respect to one another,

Fig. 6 is an end view of Fig. 5,

Fig. 7 is a view showing the shape of the pass between the rolls of Fig. 5,

Fig. 8 is a view similar to Fig. 5, but showing the forming rolls in still another position.

Fig. 9 is an end view of Fig. 8, and

Fig. 10 is a view showing the shape of the forming pass between the rolls of Fig. 8.

Referring now to the drawings, the sheet forming apparatus herein provided comprises a rolling machine including a pair of forming rolls 15 and 16 associated with one end of a receiver 17 and being spaced from one another to create a sheet forming pass therebetween. In forming the glass sheet, a charge of molten glass 18 is deposited upon receiver 17 from a pot or other suitable receptacle 19 and then passed between the forming rolls 15 and 16 which serve to reduce it to a sheet 20 of substantially predetermined and uniform thickness. As the sheet leaves the forming rolls, it passes downwardly over an inclined slab 21 and is deflected into the horizontal plane and received upon a series of horizontally aligned rolls 22 driven in any suitable manner and adapted to convey the sheet to and/or through an annealing leer. In order to effect the desired rotation of forming rolls 15 and 16, there may be carried by these 'rolls at one end thereof, sprockets 23 and 24 respectively, about which is trained a sprocket chain 25 which serves to drlve the forming rolls in opposite directions as 1nd1- cated by the arrows in Fig. 1.

The forming rolls 15 and 16 are received at each end within a supporting frame 26 mounted upon a cradle 27 supported upon rollers 28 carried by the base member 29. The receiver 17 is also supported upon cradle 27. Carried by the cradle 27 is a worm gear 30 meshing w1th and being driven from a worm 31 keyed to drive shaft 32. .From the above, it will be readily apparent that upon rotation of worm 31, the cradle 27 can be rocked upon the rollers 28 so as to tilt the forming rolls 15 and 16 and also the receiver 17 as a unit.

The lower forming roll 15 is journaled at each end within a bearing block 33 received within the respective supporting'frame 26 and adjustable horizontally by suitable adjusting screws 34. The upper forming roll 16 is journaled at each end-within a bearing block 35 also mounted within the respective supporting frame 26 and being adjustable horizontally by the adjusting screws 36. The upper roll is likewise adjustable vertically with respect to the lower roll by adjusting screws 37. Thus, the bearing blocks 33 and 35 which support the forming rolls at either end can be independently adjusted in a direction parallel to the travel of the sheet being rolled, while the upper bearing have a perpendicular adjustment.

As pointed out above, the aim of this invention is the provision of a method and means by which the pass or aperture between the sheet forming rolls may be varied to such different operating conditions without removing the rolls or altering their shape. Therefore, according to the invention, the rolls, instead of being true cylinders, are slightly smaller at their centers than at their ends. In other words, the forming rolls gradually increase in diameter from the center to their opposite ends. Their contour is such that the normal aperture between the rolls when the axes of the rolls are parallel is substantially lens shaped as shown in Fig. 3, the top and bottom being circular arcs of large radius or some similar curve.

In operation, if conditions are such that the center of the sheet formed would be thinner at the edges with the use of cylindrical rolls, the two forming rolls 15 and 16 are set in a position approaching parallelism so that the pass therebetween, when cold and vunblocks also relation shown, much exaggerated, in Figs.

5 and 6, the actual gap between the rolls in thislcase having normally the shape shown in Fig. 7. The inclination of the rolls would be regulated to just counteract the influences tending to distort the aperture, and the actual shape of the aperture in operation would then be that of Fig. 10. On the other hand, for conditions for which cylindrical rolls would be correct, an intermediate setting would be 1 v selected such as shown in Figs. 8 and 9.

The inclination of the axes of the rolls in the above adjustments might appear to 'produce a twisting action on the sheet. However, the actual adjustments would be so.

slight that this effect would not be noticed, especially on materials like hot glass which would leave the rolls in a viscous and ductile condition. It is important, nevertheless, that posite directions to maintainthe direction of travel of the sheet formed.

It is to be understood that the form of the invention herewith shown and described'isto be taken as the preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. In apparatus for the manufacture of sheet glass, a pair of forming rolls adapted to receive a charge of molten glass therebetween and reduce it to sheet form, said rolls being normally relatively narrower at their centers than at their ends, and means for inclining the rolls relative to one another in a direction parallel to the travel of the sheet being rolled.

2. In apparatus for the manufacture of sheet glass, a pair of forming rolls adapted to receive a charge of molten glass therebetween and reduce it to sheet form, said rolls being normally relatively narrower at their 1 centers than at their ends, and means for crossing the longitudinal axes of the rolls in a direction parallel to the travel of the sheet being rolled.

3. In apparatus centers than at their ends, and means for for the manufacture of sheet glass, a pair of forming rolls adaptedv both rolls be adjusted the same amount inop- I independently adjusting the rolls in a direction parallel to the travel of the rolled.

4. In apparatus for the manufacture of sheet glass, a pair of forming rolls adapted to receive a charge of molten glass therebetween and reduce it to sheet form, said rolls being normally relatively narrower at their centers than at their ends, and means for independently adjusting either end of each roll in a direction parallel to the travel of the sheet being rolled.

5. In the method of producing sheet glass wherein a charge of molten glass is moved through a sheet forming pass created between a pair of rolls normally relativel narrower at their centers than at their en s, the step of inclining the rolls relative to one another in a direction parallel to the travel of the sheet being rolled.

6. In the method of producing sheet glass wherein a charge of molten glass is moved sheet being through a sheet forming pass created between a pair of rolls normally relativel narrower at their centers than at their en s, the step of crossing the longitudinal axes of said rolls in a direction parallel to the travel of the sheet being rolled to counteract the influences tending to distort the forming pass so that the actual shape of the pass in o eration will be of a uniform width throug out.

Signed at Toledo, in the county of Lucas and State of Ohio, this 15th day of Septem ber, 1931.

CARROLL CONE. 

